Host-Based Controller Modem
Data Addendum
AT Command Set
June 15, 1998
AT Voice Commands Reference (continued)
Lucent Technologies Inc.
Version 1.0
46
AT+VLS=? Analog Source/Destination Selection and DTMF/Tone Reporting
Requests for the modem's DTMF/Tone reporting capabilities are made using this command. For each system
configuration in voice mode (i.e., speakerphone and answering machine), the modem reports the capabilities that
are enabled for the configuration.
Also, for each configuration, the modem indicates tone-reporting capabilities for each of the three different voice
states: voice transmit data, voice receive data, and voice command state (voice idle).
TAD supports each of the following IS-101 analog source/destination configurations:
Label #
Description
0
DCE on-hook, local phone connected to Telco.
1
DCE off-hook, DCE connected to Telco.
2
DCE off-hook, local phone connected to DCE.
3
DCE off-hook, local phone connected to Telco, DCE to local phone.
4
Speaker connected to DCE, DCE on-hook (playback messages)
5
Speaker connected to DCE, DCE off-hook (call screening)
6
Microphone connected to DCE, DCE on-hook (record greeting)
7
Microphone and speaker connected, DCE off-hook (speakerphone)
AT+VSD=<sds, sdi>
Silence Detection (QUIET and SILENCE)
This command sets both the silence detection sensitivity (<sds>) and silence detection interval (<sdi>).
■
Larger values of <sds> indicate that the modem is to treat noisier line conditions as silence.
<sds> = 128 ; Nominal level of sensitivity;
−
40 dBm (default) .
<sds> > 128 ; More aggressive ; <sds>=129 is
−
39 dBm.
<sds> < 128 ; Less aggressive; <sds>=127 is
−
41 dBm.
■
The <sdi> specifies the amount of time the modem shall wait before reporting silence to the DTE. It is used for
determining :
Presumed hang-up (SILENCE), after which the modem sends <DLE>-s to DTE.
Default is 5 seconds.
AT+VSM=<cml>,<vsr> Compression Method and Sampling Rate Specifications
This command enables the compression method and sampling specifications where cml = compression method
label and vsr = voice sampling rate.
AT+VSM?
Returns the numeric and string labels of the compression method currently in use, and the
sampling rate currently in use.
AT+VSM=?
Reports the voice compression methods supported by the DCE, and the voice sampling rates at
which they are supported: The default is 129,8000 (16-bit linear, 8.0 kHz )
✟
128, 8-bit linear, (7200, 8000, 11025)
✟
129, 16-bit linear, (7200, 8000, 11025)
✟
130, 8-bit A-law, (8000)
✟
131, 8-bit
µ
-law, (8000)
✟
132, IMA ADPCM, (8000)